[Bowlinsr1962]

Thanks for allowing me into the group. I recently bought a 2008 Cabriolet that had 116,000 miles on it. I’ve notice now that I’ve put about 5,000 miles on that the oil has to be topped up to full about every 1,000 miles give it take. It takes a full quart each time I top it up and is right at the full mark. Not a big deal if you’re not driving 120 highway miles. Unfortunately I am. Is this considered high consumption? I’ve check for leaks, blow by, and smoking and none of the symptoms are there. Not sure where the oil is going. Checked the antifreeze and it’s full and of the right color. I’ve looked into Lucas oil stabilizer to add after the next 1,000 mile top off. Should I try this to slow the consumption? I was using 5w30 Mobile 1 and changed it again once I noticed it was using oil. Went to the Mobil 1 Euro 0w40 and no change. Now I’m just topping off each time with 5w40. Thoughts on whether the Lucas will help this issue or should I step up to a thicker viscosity oil? Thanks.

 

[jwight]

Welcome to SCoA!

That's not normal for these cars. Most 451s use minimal, some zero, oil between changes. A higher viscosity oil probably won't help that much and will reduce engine efficiency. An engine teardown would find the leak, but it's cheaper to keep topping up the oil.....

 

[Bowlinsr1962]

What do you think about using the Lucas the next time I top it up?

 

[InjuredAgain]

I had the same experience with a 22 year old Mazda Miata nearing 190k miles. Early in its life, the maintenance was possibly a bit unsure, and almost definitely did not include the use of synthetic oils that would have prevented the vast majority of the wear. By the time I got it with 138k miles, it would burn a quart every 1500 or so miles. At that rate, the catalytic converter cleaned it up so well that I could never see any hint of blue smoke, even at night with a car's headlights shining right behind me. I think any smaller, high revving engine will eventually encounter some wear unless it is fed a diet of synthetic oil and regular changes from the beginning.

The first generation Miata engine had a reputation for the oil control rings to become gummy and start to seize up after a while. I tried various cylinder soak treatments to try and free them up with limited success. I never did disassemble the engine but after consulting with engine builders, the consensus was that I was looking at an engine rebuild or a swap with a newer engine.

I tried higher viscosity oils, and the Lucas is basically a viscosity improver that increases mimics using a higher viscosity oil. Those primarily help in instances where you might have leaking stem seals, but you would notice that by a very smoking warm startup after sitting for some tens of minutes. Since you don't see that, it's most likely you just have a worn engine.

 

[bobarb]

Maybe a compression test would help diagnose the problem.

 

[InjuredAgain]

Maybe a compression test would help diagnose the problem.

In the case of my Miata, the compression rings were fine but the oil control rings were not. I had even and high compression numbers in all cylinders that still met as-new specs.

 

[Norm62]

I have a 2008 Cabriolet I bought brand new, currently it has 67000 miles. I've had the same problem since day one. The Smart dealership told me several years ago this is normal. I just keep an eye on it and makes sure it doesn't get too low.

 

[smark]

Pull the plugs, see if the tips are oil soaked. While you got each one out. Do a compression test, as mention above.

 

[Jo e Lefors]

I had a 2008 smart and currently own a 2009 with 54,000 miles on it, both only used half quart between oil changes, which to me is more normal than a quart every 1000 miles.

 

[Norm62]

I changed the plugs last month. The old ones had a little carbon but that was it.

 

[jimvw57]

I found an oil leak just above the oil filter, there is a bolt that blocks the oil passage for the turbo. It only leaks when the engine gets higher revs and doesn't leak much when parked or sitting still at idle. Was tough to find, added some gasket sealer to the threads and screwed it in tight, no more oil use. Well it does use a quart in 7,000 miles but I won't worry about that.

look at the front of the muffler and see if it is wet with oil.

https://www.smartcarofamerica.com/forums/f353/oil-leak-113738/#post1300490

this is the bolt that was leaking. air flow from driving would give some specks on the rear of the car but no puddles when it was parked